Maintaining Cold Chain Integrity

Managing a food supply chain has inherent challenges that require all players in the supply chain to adhere to stringent operational practices in order to ensure the product is safe for consumption once it reaches the end consumer. When fresh or frozen foods are being transported, especially in a global supply chain, the procedures and equipment needed to maintain the integrity of the cold chain are elevated to a more critical role.

Food safety and quality are drivers

Two issues that continue to drive best practices for managing the cold chain are food safety and food quality, according to Bob Biesterfeld, director of transportation, produce sourcing, for C.H. Robinson.

“From a legislative standpoint, we’ve had different versions of the Sanitary Food Transportation Act in place since 1990,” he says. In general, the regulations assure that certain requirements related to food transportation are being met along the supply chain from shipper, to carrier, to receiver.

Among other responsibilities, the shipper is charged with inspecting the equipment that will transport the product to the final destination.

“Typically, the shipper is looking at the condition of the trailer to make sure the walls are in place, that there are no holes in the roof or floor, and that the trailer is ‘clean, dry, and odor-free,’” explains Biesterfeld. “In addition, some food shippers will contractually require their carriers to meet certain guidelines through legal means. For example, they will contractually require the carrier to certify that the trailer hasn’t been used to haul refuse or hazardous material.”

Carriers, likewise, are also responsible for the quality and the condition of the trailers and equipment that are used during the transportation of food products.

“For produce deliveries, that could include physical inspection of the product as well as the boxes and cartons. Wet or weakened packaging may indicate that there was a breach in temperature during transportation.”

It’s also increasingly common for the receiving party to rely on temperature-recording devices that have been installed on the trailer, which can alert them to any deviations from the required temperature range.

“Clearly, food safety has become a more important issue in the minds of consumers in recent years, in part because of several high-profile food illness outbreaks,” says Biesterfeld. “Additionally, food quality is very much related and equally important.”

There’s a direct correlation between maintaining the integrity of the cold chain and the shelf life of food products, notes Biesterfeld. And while science can support the correlation, the economic realities brought about by the recession means that on occasion, food quality goals are more difficult to achieve for some in the supply chain, including transportation providers.

“Sometimes the carrier will be instructed to run a refrigerated unit at a continuous setting, where the refrigeration unit remains in the ‘on’ position in order to maintain a set temperature throughout the life of the load,” explains Biesterfeld. “But, that’s more expensive for a carrier compared to operating the refrigeration unit in a ‘start/stop’ mode, which turns the reefer unit on and off to keep the load within a certain temperature range.”

This can have unacceptable consequences for some shippers, such as a lettuce shipper, who expects their shipment to be maintained at a constant 36 degrees Fahrenheit.

“If a carrier chooses to use a start/stop setting on that reefer unit, the air temperature could reach 42 degrees, for instance, which could potentially impact the quality of the product,” says Biesterfeld.

Not only that, there’s a good chance that the shipment will simply be rejected.

“Nearly all food retailers have specific quality assurance specs that must be adhered to by the transportation providers,” Biesterfeld says. “Using the lettuce example, if the receiving spec stipulates a temperature range between thirty-four and forty degrees and the product arrives at forty-one or forty-two degrees, there’s a high likelihood that it will be turned away.”

The tough economy also means that some carriers are trying to get extra mileage out of their trucks and trailers, adds Biesterfeld.

“The overall age of the fleet is older today than it has been at any other time in the past, which can lead to more mechanical problems, breakdowns, and other issues that can compromise the cold chain.”

Admittedly, the decision to purchase new equipment becomes tougher for many companies in a down business cycle. But, the good news is that trailer manufacturers are unveiling new equipment offerings that are dramatically improving their long-term value.

Great Dane Trailers’ ThermoGuard is one example that stands out. The product consists of an exclusive glass reinforced thermoplastic reefer interior liner that helps maintain the insulation capabilities of the trailer.

Most refrigerated trailers in use today are insulated with polyurethane foam, which is lightweight, cost effective, and versatile in the manufacturing process. And, while it offers excellent insulating performance at first, the foam loses its ability to insulate effectively as the trailer ages. The degradation also adds to fuel costs because the trailer’s cooling unit is forced to work longer, and therefore consumes more fuel to keep the trailer at the desired temperature.

By contrast, ThermoGuard can potentially reduce cooling unit run time by more than 1,000 hours over a five-year period. It’s also incredibly thin, strong, and lightweight compared to traditional trailers—up to 200 pounds lighter. Great Dane’s ThermoGuard trailer is also constructed from recyclable materials, which boosts its environmental attractiveness.

At the same time, software and technology tools that can improve visibility and monitoring of the food supply chain is becoming more affordable, notes Biesterfeld.

Temperature-recording devices that can be placed inside a trailer can cost as little as $25, he says.

Furthermore, advances in the TRUs (transport refrigeration units), and increased use of GPS and GPRS-based technology that can track and monitor truck movement and conditions inside the trailer are allowing shippers and receivers to actively manage the cold chain, says Biesterfeld.

In fact, active cold chain management is “one request we’re hearing from our customers more frequently. They want the ability to impact in-transit temperature at any point (of the transportation move),” he adds.

Global food chains add complexity

According to the U.S. Food and Drug Administration, between 10 and 15 percent of all food consumed in the U.S. is imported. In addition, nearly two-thirds of the fruits and vegetables—and 80 percent of the seafood—consumed by Americans are sourced from outside the U.S.

Food exports from the U.S. are also on the rise with new and sizeable markets opening up. In November, India’s government voted to allow more direct foreign investment in the country’s huge retail industry. The move is a major victory for global giants like Walmart, Carrefour, and Tesco as well as the food sector in India, which stands to benefit from huge investments in food storage facilities and the overall transportation network.

Simply put, the food supply chain—and by extension the cold chain—is becoming more global. Price, variety, and the ability to maintain the cold chain for extended periods are helping to drive the trend, says Dermott Crombie, vice president of global business and marine solutions for Thermo King.

A typical coast-to-coast truck move in the U.S. takes five days. “But if you’re talking about kiwis from New Zealand, for instance, you’re now looking at 6 weeks,” says Crombie. This time frame takes cold chain management to a new level, he says.

Although a considerable amount of U.S. food imports are sourced from NAFTA partners, a growing portion is coming from developing countries, especially China, India, and countries in Eastern Europe.

While there’s a perception that harvesting, processing, and transportation methods in developing countries are inferior to those in the industrialized world, that’s not necessarily the case, Crombie points out.

“In my experience, preparation of the box [reefer container] that is going to be handling food cargo is all done very responsibly, whether it’s in a developed country or not. Companies are very conscientious about their responsibility to maintain cold chain integrity. Hygiene at every stage of the food supply chain is vital, including the box itself,” he says.

The banana trade from Central America is one example. “In Costa Rica, there are endless numbers of banana plantations. All of the major fruit brands are there. They have their own people on the ground conducting temperature and other quality tests and assuring quality all the way from the growing cycle through to the transportation and distribution.”

Bananas are cut, washed in cold water to get the temperature down, and put directly into the reefer container at the plantation, says Crombie. Once the fruit is in the container and it’s powered up, the equipment is able to maintain a highly stable and consistent environment, despite the outside conditions, which may begin with a two-day drive on poor roads to the seaport followed by many days on the water.

“The level of control over the reefer for long distance cargo is remarkably good,” says Crombie. “There’s no break in the cold chain, even during loading and unloading. The refrigeration unit has a very elaborate electronic controller that records everything that happens during the transportation process. Shippers can monitor the condition of the cargo starting at the plantation all the way to final delivery, even if the cargo is on the water for weeks. Arguably, there is better temperature control on long distance marine voyages than on five-day coast-to-coast truck moves.”

Building a better box

Ocean cargo transportation has evolved significantly since Malcom McLean conceived the idea for an intermodal container in 1956. Not coincidentally, Thermo King introduced the world’s first refrigerated container that same year.

In recent years, advancements in the reefer container have single-handedly made it possible to support global food supply chains.

Of course, the ongoing quest to enhance food safety and quality are the perennial drivers.

Referring to the banana trade, Crombie says that for every hour the fruit sits at the ambient temperature, for example 83 degrees Fahrenheit, it ‘costs’ one day in shelf life.

“It’s in everyone’s best interest to get that temperature down as fast as possible,” he emphasizes. “Thermo King’s machines are very powerful in terms of their ability to cool down cargo quickly. The MAGNUM reefer is the best on the market for getting cargo cooled down quickly and keeping it as close as possible to the ideal carrying temperature. This accuracy is key to improving shelf life.”

The MAGNUM can maintain a -35 degrees Celsius set point and unlike traditional units, which are effective in moving deep frozen products for the first 5 years, the MAGNUM offers enough cooling capacity to maintain -29 degrees Celsius throughout the 15-year life of the box. This not only makes the container more profitable, it also eliminates repositioning charges for deep frozen shipments.

Two years ago, the company introduced the next generation MAGNUM, called the MAGNUM PLUS, which offers improved energy efficiency.

“Once this reefer gets the cargo down to the ideal temperature, it’s very careful as to how much energy it uses to keep it there,” Crombie explains. “On average, a traditional reefer draws five kilowatts, compared to the MAGNUM PLUS’ 1.7 kilowatts, which translates to a sixty-plus percentage reduction in energy consumption, while at the same time providing better temperature control and [temperature] pull-down.”

Aside from continual improvements in reefer technology, including temperature and humidity control, Thermo King is hoping to drive more shipments from air cargo to more cost effective alternatives, namely ocean and rail.

“The SuperFreezer unit is unique in the market. It keeps cargo at -60 degrees Celsius. Primarily, it’s targeted towards high-value cargo like sashimi-grade tuna, swordfish, and sea urchins,” says Crombie—in other words, cargo that that has historically been transported by air cargo. d